Which one is the safest way to store bitcoins? I often hear that becomes thefts. I guess some of them are not heard even.
I'm used electrum for desktop. So far I haven't problem with their wallet. It's easy to use and have more security features. Also you don't need to download blockchain data, just sync it with your internet connection.
I am using electrum too, same wallet both in my PC and my laptop , with its nice recovery option via its seed, if I buy a new PC, I can install it there too the same wallet. I am using Linux which makes me a bit safer than windows users from phishing and troyans but not 100% safe. Another thing to keep in mind is to keep your system up to date as much as you can. For ultimate security go for hardware wallet which are malware proof, if Trezor is expensive for you , you can buy a ledger wallet HW.1 which is the cheapest hardware wallet you can get. In the end the security of your coins depends on how well the user saves them.